3D Printed Cement Bluetooth Speaker!

Hey Everyone what's up!

So this is my 3D Printed Cement Bluetooth Speaker!

Fun Facts, It's made out of cement and some custom 3D Printed parts.

This Cement Speaker is powered by a 3.7V 5.2Ah Li-ion Battery Pack and I used an old Bluetooth speaker Circuit to operate it.

In this instructable, I'm gonna show you guys how I built this speaker in few easy steps

Let's get started!

Materials for Cement Middle Structure-

• Cement
• SAND
• Cardboard (for Paper Mache)
• Plastic Board (sun board)
• Wooden or any sturdy material (for Mould base)
• Water
• HOT Glue (for preparing Mould)
• Patience

3D Printed Parts Required-

• Front Part
• Back Part
• Handle
• Screws to hook everything together.

Electronics-

• Speaker 8Ohms
• Rocker Switch SPST
• Bluetooth Speaker Circuit
• LED (5mm)
• Li-ion Battery Pack
• Micro USB Charging moduled port
• Wires as per required

Project Planning here is pretty straightforward.

Bluetooth speaker contains two main parts, one is the body itself and the other is the driver.

Driver circuit contains the Bluetooth Chip, it also contains an onboard amp IC which amplifies the audio picked up by the Bluetooth chip, and then the audio gets output through the speaker.

This whole structure is then powered by a Li-ion Cell and to charge that cell, we have a Li-ion cell charging ic.

The Body is always designed in such a way that distortion inside the speaker is not much and it won't negatively affect the sound.

For Body, I first designed a Cement Hexagon Structure in Fusion 360. I made its Front and Backside from PLA, Front part Holds the Speaker and ON-OFF Switch in its place along with an Indication LED. The backside contains the charging Port. (STEP File is attached)

Also, Because I have used cement as the middle part of this Bluetooth speaker, it became quite heavy, around 2kg.

Anyways, After Finalizing this whole structure, I then 3D Printed the Front/Back Part with RED PLA at 20% Infill and Handle with transparent PLA at 10% Infill.

After this, I prepared the Cement Hex Structure by a Makeshift Mould that I made with Sunboard and Hot glue.

In order to make the Cement HEX Structure, I first tried to make a 3D Printed Mould but Making the 3D Printed mold would take too long so I use the universal method which was to make a DIY Mould with Sun Board and HotGlue.

• I First Cut down the Sun Board into two different thicknesses, 65mm for inside and 95mm for outside. The length of both of these boards was the same 156mm.
• After this, I took a sturdy piece of plastic sheet that I had lying around and use it as a base for the mold.
• I First start with placing the inner 65mm layer on the mold base with hot glue, after that, I place the outside layer which was the 95mm layer.
• I then added extra hot glue to each layer's edges, boundaries, and all the spots that could potentially leak.
• at last, to check if my mold was perfectly made, I filled it up with water and check for leakage.
• It didn't leak and now we have a simple "Use and throw Cement Mould"

Preparing Cement Mix was easy, I took 600g of Cement and added 300g of sand to it. I slowly added a little bit of water to mix both of them together, we basically want pancake mixture concentration here.

To give the concrete little more strength, I prepared a cardboard paper mache solution which I later added to the cement mix. paper mache will act as a binding agent and it will increase the overall strength of this structure.

(for reinforcement of concrete)

At last, I added the cement mix to the mold and then let it set.

after 2 days, the cement has completely dried up so I removed it out of the mold (mold got destroyed in this process) and the result of this whole process came out just fine.

For Painting the Cement Structure, I used white metal paint here but you could use cement paint here as well.

A trick to make this Cement Structure a little bit cooler is to use wood paints with wood varnish mixed.

I used three parts in this build which were-

• Front Body
• Back Body
• Handle

I've added their Step file above so you can download all three parts or modify them.

Print Front and Back body at a lower infill (10-20%) with Brim attached because they might warp while printing.

Handle requires Generative support in the middle section.

(please let me know if there's something wrong here)

Assembly is pretty straightforward here,

I first added the Bluetooth speaker Circuit/Speaker setup to the front body.

The front Body holds the Speaker in its place, I then added a Rocker Switch (SPDT) on the front body and a 5mm indicator led.

On the Backside of the Back Body, I added a 5mm Barrel DC Jack for charging this whole structure.

For Wiring Connections, please see the attached Schematic/Wiring Plan.

After Wring, Put the Circuit in between the Front and Back body and close the Lid from both sides.

Both Front and Back Bodies are secure with HEX Body by M2 Screws and Bolts.

After the assembly, all that is left to do is the final test, which is to play some loud stuff with this BT Speaker.

*Watch the video*

I have an idea for a future version of this Cement Speaker, I will use a better Audio driver in it and add another speaker which will be mounted on the other side (backside).

Then, we can also make two or four of these speakers and play them all together, kinda like surround sound!

But that is for the future version!

I hope this Instructable was helpful, if yes then hit that FAV Button! or leave a comment if you need any help in this project.

Peace!